In vitro inhibition of lipid peroxidation in fish by turmeric (Curcuma longa)

The beneficial effects of ∈-3 fatty acids on human health have been well documented. Fish and fish oils are the richest sources of ∈-3 fatty acids. However, due to their high degree of unsaturation, they are highly susceptible to lipid peroxidation. Regular consumption of peroxidised oils may represent a risk factor for the induction and development of atherosclerosis. In view of the above reports, it was considered necessary to study the effects of tumeric on fish lipid peroxidation during standard cooking practices and on time-dependent changes in the peroxidation of fish homogenate. The antioxidant effect of α-tocopherol was also studied to confirm the relevance of the study. The results suggest that turmeric may be considered as a safe, cheap and readily usable antioxidant for food preparations.     

Evaluation of the radioprotective effect of turmeric extract and vitamin E in mice exposed to therapeutic dose of radioiodine

The aim of this study was to evaluate the radioprotective effect of turmeric extract (40 mg/kg body weight) and vitamin E (α- tocopherol acetate, 400 IU/kg body weight) supplementation on lipid peroxidation, reduced glutathione and antioxidant defense enzymes in various organs like liver, kidney and salivary glands at 24 h in adult Swiss mice. ¹³¹Iodine exposure significantly increased lipid peroxidation in kidney and salivary glands in comparison to control animals. Pre supplementation with turmeric extract for 15 days showed significant lowering of lipid peroxidation in kidney. On the other hand vitamin E pre supplementation showed marked reduction in lipid peroxidation in salivary glands. Reduced glutathione levels decreased significantly in liver after radiation exposure. However, pre supplementation with turmeric extract and vitamin E did not improve glutathione levels in liver. In conclusion, we have observed differential radioprotective effect of turmeric extract and vitamin E in kidney and salivary glands. However, Vitamin E seems to offer better radioprotection for salivary glands which is known to be the major site of cellular destruction after radioiodine therapy in patients.     

Genes of renin angiotensin system and coronary heart disease

The levels of cytotoxic aldehydic products in different culinary oils, with or without thermal stress, (routine domestic or commercial frying) were determined by thiobarbituric acid method. The results showed that (i) thiobarbituric acid reactivity was much higher in edible oils rich in polyunsaturated fatty acids than those rich in saturated fatty acids or monounsaturated fatty acids, even without thermal stress, (ii) the lipid peroxide levels were in proportion to the duration of thermal stress, (iii) nature of the container used (steel, iron or teflon-coated) had no significant effect on the extent of lipid peroxidation under identical conditions of thermal stress and (iv) thermally stressed oils collected from hotels and roadside caterers contained higher levels of cytotoxic aldehydic products, when compared to oils thermally stressed under domestic frying conditions. These results suggest that dietary ingestion of thermally or autoxidatively stressed polyunsaturated fatty acid rich culinary oils is more harmful compared with those similarly treated oils rich in saturated fatty acids and monounsaturated fatty acids.     

Evaluation of oxidative stress in pregnancy induced hypertension

This work was undertaken to investigate correlation between oxidative stress and initiation of pathogenesis of pregnancy induced hypertension (PIH). Fifty primigravidae in age group of 20–35 years and gestational age 28–42 weeks with PIH were taken as cases. Twenty healthy primigravidae with no medical and surgical complications of pregnancy and with blood pressure ≤140/90 mm Hg served as controls. The cases were again subgrouped as severe preeclampsia (12 in number) and mild pre-eclampsia (38 in number). All of them were evaluated for serum malondialdehyde (MDA), Serum vitamin E and plasma vitamin C levels. The serum MDA levels were raised significantly in women with mild preeclampsia (P<0.01) and in women with severe preeclampsia (P<0.01) in comparison to normal primi gravida. The serum vitamin E levels were decreased in primi gravida with mild preeclampsia (p<0.1) and in primi with severe pre eclampsia (P<0.1) in comparison to normal primi gravida but the fall was not statistically significant. There was a significant fall (P<0.05) in the vitamin C levels in primi with mild preeclampsia than in the normal primi. The vitamin C levels in severe preeclamptic patients were lower than the normal primi but the fall was not statistically significant (P=0.10). The serum MDA and vitamin E showed a negative correlation in all the cases. The serum MDA and plasma vitamin C also showed a negative correlation in the control and study group. This observation suggests that in hypertensive disorders of pregnancy there is an imbalance between lipid peroxidation and antioxidant vitamin status because of oxidative stress. The decreased serum concentrations of the antioxidant vitamins supports the hypothesis that lipid peroxidation is an important causative factor in the pathogenesis of preeclampsia. The rise in antioxidants is probably to compensate the increased peroxide load in severe preeclampsia.     

Protective effect of ascorbic acid against oxidative damage induced by hydrogen peroxide in cultured human peripheral blood lymphocytes

Hydrogen peroxide is one of the reactive oxygen species for cellular injury. It is overproduced during oxidative stress and is known to damage proteins, nucleic acids and cell membranes. The present study was aimed to study the protective effect of ascorbic acid against the toxic doses of hydrogen peroxide using lipid peroxidation and cytokinesis blocked micronucleus assay. Hydrogen peroxide was studied at 50, 100 and 200μM and was found to increase a dose dependent increase in lipid peroxidation and micronuclei frequency. The treatment of 100 and 200μM of hydrogen peroxide separately along with 20, 40 and 80μM of ascorbic acid showed a dose dependent decrease in the lipid peroxidation and micronuclei frequency. The results suggest a protective effect of ascorbic acid against the hydrogen peroxide induced oxidative damage in cultured human peripheral blood lymphocytes.     

Oxidants and antioxidants in hypoxic ischaemic encephalopathy

In the present study, the role of serum lipid peroxide and serum nitric oxide as oxidants and erythrocytic superoxide dismutase & serum vitamin E as antioxidants were determined in the 50 neonates with hypoxic ischaemic encephalopathy. (HIE) as against 25 healthy neonates as controls 50 patients of HIE were further divided into two groups i. e. mild and moderate HIE patients. All subjects were in the age group of 37–41 weeks of gestation. The levels of serum lipid peroxide, serum nitric oxide and erythrocytic superoxide dismutase were significantly elevated in both groups of neonates with HIE than those of controls (P<0.001), whereas serum vitamin E levels were significantly decreased in both groups of HIE patients than those of controls (P<0.001). A positive correlation was obtained between serum lipid peroxide and erythrocytic superoxide dismutase (r=+0.86). Alterations in the status of oxidants and antioxidants indicate role of free radicals in the development of HIE.     

Cardioprotective response to chronic administration of vitamin E in isoproterenol induced myocardial necrosis: Hemodynamic,biochemical and ultrastructural studies

The present study evaluated the cardioprotective potential of vitamin-E by studying its effect on hemodynamic parameters, lipid peroxidation, myocyte injury marker and ultrastructural changes in model of isoproterenol-induced myocardial necrosis in rats. Wistar albino male rats (150–200 g) were randomly divided into saline, ISP control, and vit E groups. Vitamin E group was administered vitamin E at a dose of 100mg/kg/day while saline and ISP control groups received saline orally for one month. On 29^th and 30^th day, ISP (85 mg/kg, sc) was administered at an interval of 24 h to vit E and ISP control rats. On 31^st day, rats of all groups were anesthetized and hemodynamic parameters were recorded. At the end of experimentation, animals were sacrificed; hearts were excised and processed for biochemical and ultrastructural studies. ISP administration produced marked cardiac necrosis as evidenced by significant decrease in my ocardial creatine kinase-MB as well as increase in malonaldialdehyde levels. ISP-induced myocardial necrosis resulted in myocardial dysfunction as evidenced by significant depression in heart rate and mean arterial pressure in the ISP control group as compared to saline control. Salient ultrastructural changes including extensive loss of myofibrils, muscle necrosis, loss of mitochondria, and formation of several intracytoplasmic vacuoles and lipid droplets further confirmed the ISP-induced myocardial damage. However, subsequent to ISP challenge, vit E treatment significantly preserved the myocardium by restoring myocardial CK-MB activity, inhibiting the ISP-induced lipid peroxidation and ultrastructural changes. Additionally, pre-and co-treatment of vit E prevented the deleterious ultrastructural changes caused by ISP. These beneficial effects of chronic vit E treatment also translated into significant restoration of the altered hemodynamic parameters. The present study clearly demonstrated the cardioprotective potential of vit E at dose of 100 mg/kg in ISP-induced model of myocardial necrosis in rats. The significant restoration of altered hemodynamic parameters, myocardial CK-MB activity, prevention of ISP-induced rise in lipid peroxidation and ultrastructural changes may confirm its cardioprotective effect.     

Garlic Oil and Vitamin E Prevent the Adverse Effects of Lead Acetate and Ethanol Separately as well as in Combination in the Drinking Water of Rats

Daily feeding of drinking water containing lead acetate (160 mg/l) or 10% alcohol by volume or a combination of both to rats for a month produced certain deleterious effects through oxidative stress. Both heavy metal lead and alcohol are capable of doing such damages. The deleterious alterations observed were in the parameters of blood, serum and tissues, viz; Hb, Pb, proteins, lipids, lipid per oxidation, Vitamins C and E levels and enzyme activities of AST, ALT, and catalase. Simultaneous feeding of either of the two antioxidants garlic oil (GO) and vitamin E at equal doses of 100 mg/kg/day, to the rats counteracted the deleterious effects of the above two chemicals significantly. The maximum damage was brought about by feeding of drinking water containing both lead acetate and alcohol. The protective effects of GO and Vitamin E were not significantly different. The mechanism of actions of the Vitamin E and GO is probably due to their efficiency as detoxifying agents and antioxidants, to scavenging free radicals as well as an independent action of GO on the removal of lead salt as lead sulfide.     

Effect ofOcimum sanctum (Tulsi) and vitamin E on biochemical parameters and retinopathy in streptozotocin induced diabetic rats

This study was carried out to see the effect of the aqueous extract ofOcitum sanctum Linn (Tulsi) with Vitamin E on biochemical parameters and retinopathy in the streptozotocin-induced diabetic albino male rats. Adult albino male rats weighing 150–200 gm were made diabetic by intraperitoneal injection of streptozotocin in the dose 60 mg/kg in citrate buffer (pH 6.3). The diabetic animals were left for one month to develop retinopathy. Biochemical parameters like plasma glucose, oral glucose tolerance and glycosylated hemoglobin HbA_1c, were measured along with lipid profile, and enzymes like glutathione peroxidase (GPX), lipid peroxidase (LPO), superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) in normal, untreated diabetic rats and diabetic rats treated withOcimum sanctum L extracts and vitamin E. Fluorescein angiography test was done for assessing retinopathy. Results on biochemical parameters were analyzed statistically by using ANOVA followed by Dunnet's ‘t’-test. A p-value of <0.05 was considered as significant. Evaluation of biochemical profile in treated groups showed statistically significant reduction in plasma levels of glucose, HbA_1c, lipid profile and LPO, and elevation of GPX, SOD, CAT and GST. Treatment of the diabetic animals withOcimum sanctum and Vitamin E, alone and in combination for 16 weeks showed reversal of most of the parameters studied including plasma glucose levels. Angiography showed improvement in retinal changes following combined antidiabetic treatment.     

Oxidative injury and antioxidant vitamins E and C in Schizophrenia

Susceptibility of Schizophrenic patients to lipid peroxidation relative to healthy control subjects was investigated by measuring the malondialdehyde (MDA) levels in plasma. The main finding was that Schizophrenic patients were more susceptible than control subjects to oxidative damage as evident from increased MDA levels in plasma. Antioxidant levels are also depleted in Schizophrenic patients when compared to normal subjects as evident from decreased levels of vitamins E and C in the plasma. Impaired antioxidant defense and increased lipid peroxidation suggests that treatment with antioxidants (Vitamin E, Vitamin C, beta carotene) at the initial stages of illness may prevent further oxidative injury and deterioration of associated neurological deficits in Schizophrenia.     

Effect of vitamin E supplementation on oxidative stress in hemodialysis patients

Hemodialysis represents a chronic stress status for its recipients. Many hypotheses state that this may be associated with oxidative stress. Thus, there may be deficiency of antioxidants like erythrocytic superoxide dismutase, catalase, vitamin E or increased generation of free radicals like superoxide anions. A study was carried out to investigate oxidant and antioxidant status in chronic renal failure patients undergoing hemodialysis and effect of vitamin E supplementation on these two status. Blood samples were collected from patients before and after hemodialysis and from controls. The samples were analyzed for quantitation of MDA as index of lipid peroxide, nitric oxide, vitamin E, vitamin C and enzymatic antioxidants namely erythrocyte SOD and catalase. As compared to controls, the levels of serum MDA were significantly increased and activities of erythrocyte SOD and catalase, levels of serum nitric oxide, serum vitamin E and plasma vitamin C were significantly decreased both before and after hemodialysis. The efficiency of vitamin E therapy in hemodialysis patients was assessed by re-evaluating oxidant and antioxidant status of same patients after supplementation of vitamin E. Vitamin E supplementation caused decrease in serum MDA and increase in levels of serum nitric oxide, vitamin E, vitamin C and activities of erythrocytic SOD and catalase. Our results suggest the presence of oxidative stress and the possible preventive role of vitamin E therapy in hemodialysis patients.     

Assessment of oxidative stress and antioxidant status in age related cataract in a rural population

Oxidative stress was assesed by estimating lipid peroxidation product (LPO) in the form of thiobarbituric acid reactive substances (TBARS), enzymatic antioxidants in the form of superoxide dismutase (SOD), catalase and nonenzymatic antioxidant vitamins e.g. vitamin C, β carotene and vitamin E in either serum or plasma or erythrocytes in 190 cases of age related cataract in the age group of 50–80 years. 190 cases were grouped into three morphological types namely, 73 cases of cortical, 77 cases of posterior subcapsular and 40 cases of nuclear cataract and values of LPO and antioxidants were compared with 78 cases of age matched healthy control groups. Plasma TBARS levels were cataract cases when compared with control groups. There were no significant differences in the erythrocyte levels of catalase and plasma levels of Vit E between cataract cases and control groups. No significant changes of parameters were seen among three different morphological types of age related cataract. The present study shows that the oxidative stress may play an important role in the age related cataract.     

Plasma MDA and antioxidant vitamins in diabetic retinopathy

Hyperglycemia and dyslipidemia in diabetes mellitus induce increased lipid peroxidation and peroxyl radical formation, an important mechanism in genesis of microangiopathy. We took up a study on oxidative stress, measured by plasma MDA and antioxidant vitamin status in type − 2 DM patients with and without retinopathy and compared them with a control non-diabetic group. Lipid peroxidation marker MDA was significantly elevated (p < 0.001) in both the diabetic groups whereas, serum vitamin E and vitamin C registered a significant fall (p<0.001) as compared to controls. Our correlation study revealed a significant positive association between plasma MDA with both fasting and 2hr post prandial plasma glucose (r=0.81, p < 0.001, r=0.92, p <0.001) suggesting the role of hyperglycemia in free radical production. Plasma MDA also depicted significant positive relation (p< 0.001) with all lipid parameters except serum HDLc pointing the role of dyslipidemia towards lipid peroxidation. Plasma MDA level was also found to be negatively correlated with both the vitamins (p<0.001, p<0.001) in the study group explaining their protective consumption in the oxidative process prevailing in diabetic retinopathy.     

Protective influence of vitamin E on the antioxidant defence system in the whole blood and liver of normal and alloxan-induced diabetic rats

The effect of oral administration of vitamin E for twenty-eight consecutive days on blood glucose, reduced glutathione levels, antioxidant enzymes (superoxide dismutase and catalase activities), and levels of malondialdehyde (as an index of free radical-mediated lipid peroxidation) was observed in the whole blood and liver of normal and alloxan-induced diabetic rats. It was found that oral administration of vitamin E significantly (p<0.05) lowered the blood glucose level and increased the body weight of the diabetic rats. The activities of superoxide dismutase and levels of reduced glutathione increased significantly (p<0.05) while the level of lipid peroxidation decreased.     

Lipid peroxidation and antioxidant vitamins in urolithasis

The present, study was conducted to determine the level of malondialdehyde (MDA) as an index of free radial induced lipid peroxidation and antioxidant vitamins-vitamins A, vitamin C and vitamin E in 75 confirmed cases of urolithiasis. Significantly high level of MDA (p<0.001) with significantly low levels of vitamin E (p<0.001) and vitamin A (p<0.001) with no significant decrease in vitamin C (p>0.05) were observed in the plasma of urolithiasis cases as compared to normal controls. In conclusion, it appears that a role of lipid peroxidation and oxidative function exists in the pathogenesis of urolithiasis. But, the exact mechanism how this occurs remains to be elucidated.     

Effect of methyl mercury induced free radical stress on nucleic acids and protein: Implications on cognitive and motor functions

Mercury pollution and acute neurotoxicity of mercury is well known. The recent reports suggest the adverse effect of low dose mercury, though the available literature is still silent on its mechanism. This study was therefore undertaken to probe the effect of low dose methyl mercury induced heavy metal toxicity on free radical stress and its impact on behaviour of male albino rats. Male albino rats were exposed to 1 mg/kg body wt of methylmercury chloride for seven days, on day 8 they were tested for motor and memory functions. They were sacrificed later for biochemical estimations for rate of lipid peroxidation, nucleic acids, proteins in cerebrum, cerebellum and brain stem. There was an increase in the rate of lipid peroxidation showing methyl mercury induced free radical stress. The motor and memory functions demonstrated a clear decline, besides there was a lowering in the levels of nucleic acids and proteins as compared to controls. The results are important in view of recent reports that methyl mercury induced free radical stress results in early ageing and may serve as an initiating factor more specifically for neurodegenerative disorders like Alzeihemer's disease and dementias. The current findings support the notion that incorporating dietary antioxidants like curcumin, ascorbic acid and α-tocopherol in routine diet from early age may help combat the risk of developing such disorders in ensuing years.     

Effect of Vitamin E on sP-Selectin Levels in Pre-Eclampsia

P-selectin, a cell adhesion molecule is elevated in many inflammatory conditions including preeclampsia which is characterized by generalized endothelial dysfunction and vasoconstriction presumably due to free radicals or mediators released by defective placentation. Vitamin E has been documented to protect cell membranes from oxidative damage and also decrease platelet aggregation. The role of vitamin E in pre-eclampsia is contradictory and hence the study was undertaken. Soluble P-selectin was measured by ELISA and Vitamin-E levels in plasma was estimated spectrofluorometrically. In our study the effect of supplementation of 400 IU/day of Vitamin E (a-tocopheryl acetate) to patients of pre-eclampsia showed significant decreased levels of soluble P-selectin by 2nd week as compared to patients given placebo (P = 0.005). In this short period of study no direct correlations were observed between Vitamin E or P-selectin levels with blood pressure as well as with proteinuria. Future studies may focus on the effect of a-tocopheryl acetate or the phosphate form of Vitamin-E, recently proposed to be the more active form on other inflammatory markers like IL-6, an important stimuli of P-selectin release in pre-eclampsia.     

Evaluation of comparative and combined antimutagenic potential of vitamin C and vitamin E using histidine mutant <Emphasis Type="Italic">Salmonella typhimurium</Emphasis> strains

Chemoprevention represents a new intervention strategy to control some type of carcinogenesis especially in subjects at high risk for cancer development. Experimental and epidemiological data indicate that a variety of nutritional factors including vitamin C and E are effective to lower the risk of some types of cancer. However large prospective studies have failed to find such significant association. A comparative and combined in vitro antimutagenic potential of two antioxidant vitamins ascorbic acid (vitamin C) and α-tocopherol (vitamin E) were evaluated using Ame’s Salmonella typhimurium test assay. Directly acting mutagens such as sodium azide (NaN₃) and 4-Nitro-o-phenylenediamine (NPDA), and N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) were used to induce mutation in salmonella strains TA 98 and TA 100. Vitamin C significantly (P < 0.01) and dose dependently inhibited the mutagenicity induced by all the three mutagens. The percent inhibitions of vitamin C at 15 mg/plate were 33.8% (NaN₃), 52.5 % (MNNG) and 55.4 % (NPDA). Vitamin E (15 mg/plate) was effective to inhibit mutagenicity induced by NaN3 and MNNG but did not inhibit mutation induced by NPDA. Combination of vitamins (vitamin C plus vitamin E) produced only an additive antimutagenic activity when compared to their activity at 5 mg/plate. The results of the study concluded that vitamin C is a better antimutagenic agent than vitamin E and combination of vitamins did not produce any synergistic activity.     

A study of spectrin and lipid peroxidation of red blood cell membrane in thalassaemia carrier

The aim of the present work is to understand the lipid peroxidation of RBC membrane and the spectrin protein content of RBC membrane cytoskeleton of thalassaemic carrier state (trait) of β and hemoglobin E variant (HbE). We have measured the hemoglobin (Hb), malondialdehyde (MDA) and spectrin content of RBC membrane of thalassaemic carrier. The spectrin content (α and β band) of both β and HbE carrier was not changed than normal individuals. However, lipid peroxidation of RBC membrane was significantly increased in both β and HbE trait, and Hb level was also decreased in thalassaemic carrier. It may be assumed that oxidative damage by excess lipid peroxidation may have no role on irreversible membrane damage in β thalassaemia and HbE thalassaemia carrier.     

Effect of vitamin E on platelet enzymatic anti-oxidants in the patients of myocardial infarction

Effect of administration of 600 mg. vitamin E each day, for six days, was observed on activity of some of the anti-oxidant enzymes and levels of malondialdehyde (as an index of free radical mediated damage) in the platelets of patients reperfused after myocardial infarction. It has been found that vitamin E administration significantly lowers the level of malondialdehyde in the patients. Vitamin E administration increases the activities of anti oxidant enzymes (viz. superoxide dismutase, glutathione reductase and catalase) tested both in the patients and healthy controls. Vitamin E administration causes general stimulation of anti-oxidant enzyme activities both in healthy persons and the patients, however, lowering of lipid per-oxidation upon administration of vitamin E is specific for patients. These findings exhibit beneficial role of vitamin E administration in the management of the patients reperfused after myocardial infarction.